Heat exchanger

ABSTRACT

A heat exchanger wherein elongated, secondary heat transfer elements extend transversely to passes of a primary heat transfer element and are clampingly secured thereto.

United States Patent 1 [111 3,779,311

OConnor et al. 1 Dec. 18, 1973 [54] HEAT EXCHANGER 2,867,417 1/1959 Axlander 165/183 ,70 ,877 4 l9 [751 Inventors Joseph oyco'morchlcago; 5,463,613 8/1923 i i l zer Stephen F. Pasternak, Park Ridge,

both of 111. v I Primary Examiner-Manuel A. Antonakas [73] Assgnee' gir 3 men-c Incorporated Assistant ExaminerThe0phi1 W. Streule, Jr

lcago Attorney-Johnston, Root, OKeeffe, Keil, Thompson [22] Filed: Aug. 26, 1971 & Shurtleff [21] Appl. No.2 175,264

[52] US. Cl. 165/171, 29/1573 B Y [57] ABSTRACT [51] 1111. C1 F281 l/32 A heat exchanger wherein elongated Secondary heat [58] Field of Search 165/1823, 171 transfer elements extend transversely to passes of a primary heat transfer element and are clampingly se- [56] References Clted Cured thereto UNITED STATES PATENTS 2,687,626 8/1954 Bartlowe 165/171 X 9 Claims, 10 Drawing Figures HEAT EXCHANGER BACKGROUND OF THE INVENTION It is a primary object of the present invention to afford a novel heat exchanger.

Another object .of the present invention is to enable a heat exchanger of the type commonly referred to in the art asa wire condenser" to be afforded in a novel and expeditious manner.

Heat exchangers of the aforementioned wire condenser type ha i/e been well known in the art for many years, having been extensively used in household refrigerators, and the like. Such wire condensers heretofore known in the art commonly have embodied steel tubing disposed in a serpentine pattern, with steel wires extending transversely across the passes of the tubing, in parallel relation to each other, the wires being spot welded to the tubing. Such interconnection of the wires with the tubing affords little more than point contact therebetween, and, therefore, the heat paths between such wires and tubular members have been relatively small and inefficient. It is an important object of the present invention to afford improvements over the wire condenser type of heat exchangers heretofore known in the art.

Another object of the present invention is to enable contact to be afforded between the primary and secondary heat transfer elements of heat exchangers of the wire condenser type, and the like, which is spread over a greater area than'has been afforded in such heat exchangers heretofore known in the art.

An object ancillary to the foregoing is to enable such contact to be afforded over a substantial area.

Another object is to enable heat exchangers to be afforded for household refrigerator use, and the like, which are smaller in size than heat exchangers heretofore known in the art for such uses, while having the same or greater heat transfer capacity as the heat exchangers heretofore known in the art.

Yet another object of the present invention is to enable primary and secondary heat transfer elements of wire condensers, and the like, to be constituted and arranged in a novel and expeditious manner relative to each other.

Heat exchangers, which have had tubular members clarnpingly mounted in outwardly opening slots have been heretofore known in the art. An example of such a heat exchanger is that shown in US. Letters Pat. No. 3,546,763, which issued Dec. 15, 1970 to Stephen F. Pasternak. In the making of such heat exchangers, the tubular members have been inserted, in flattened condition, through the outer portions of the slots and then, by the application of internal pressure, or external pressure, or both, the tubular members have been expanded into close fitting relation to the outer bounda-- ries of the slots, to thereby clarnpingly engage the tubular members in the slots. However, insofar as is known, heat exchangers embodying solid heat transfer elements clarnpingly engaged in slots with sufficient force to hold the solid element stationary therein have not been heretofore known in the art, and it is an important object of the present invention to enable such construction to be afforded.

An object ancillary to the foregoing is to afford a method of making heat exchangers wherein a heat transfer element is clarnpingly engaged in a slot in the aforementioned manner, which is equally applicable to solid and tubular heat transfer elements.

Another object of the present invention is to enable a novel heat exchanger to be afforded wherein primary and secondary heat transfer elements are connected together in a novel and expeditious manner.

A further object is to afford a novel heat exchanger embodying a tubular member disposed in a pattern affording a plurality of laterally spaced passes, with other heat transfer elements extending between and secured, in a novel and expeditious manner, in slots formed in the tubular member.

An object ancillary to the foregoing is to afford a novel heat exchanger embodying a flanged tubular member, with slots formed in the flanged portions thereof, and with secondary heat transfer elements secured in the slots in the flanges in a novel and expeditious manner.

Another object of the present invention is to enable a novel heat exchanger to be afforded which is practical and efficient in operation and which may be readily and economically produced commercially.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show preferred embodiments of the present invention and the principles thereof and what we now consider to be the best mode in which we have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a top plan view of a heat exchanger embodying the principles of the present invention;

FIG. 2 is a fragmentary, side elevational view looking in the direction of the arrows 22 in FIG. 1, but showing the heat exchanger prior to completion of the construction thereof;

FIG. 3 is an enlarged, fragmentary, detail sectional view taken substantially along the line 33 in FIG. 1, and showing a tool associated therewith for performing an operation thereon;

FIG. 4 is an enlarged, fragmentary side elevational view of a portion of the heat exchanger shown in FIG.

FIG. 5 is a fragmentary, detail sectional view, similar to FIG. 3, but showing both sides of a modified form of the present invention;

FIG. 6 is a view similar to FIG. 3, but showing another modified form of the present invention;

FIG. 7 is a fragmentary, top plan view looking in Jhe direction of the arrows 77 in FIG. 6;

FIG. 8 is a view similar to FIG. 3, but showing another modified form of the present invention;

FIG. 9 is a fragmentary, top plan view looking in the direction of the arrows 9-9 in FIG. 8; and

FIG. Isa side elevational view of tubular members embodied in the heat exchangers shown in FIGS. 1-9, but showing the tubular members in an early stage of the manufacture of the exchangers.

DESCRIPTION OF THE EMBODIMENTS SHOWN HEREIN A heat exchanger 1, embodying the principles of the present invention, is shown in FIGS. 1-4 of the drawings to illustrate the presently preferred embodiment of the present invention, and the presently preferred method of making a heat changer in accordance with the principles of the present invention.

The heat exchanger 1 embodies, in general, a heat transfer element in the form of an elongated tubular member 2, bent into a serpentine pattern to afford transversely spaced elongated passes 4, 5, 6 and 7, the adjacent pairs of which are interconnected by return bends 8, 9 and 10, respectively, with a plurality of elongated, solid, secondary heat transfer elements 11 extending transversely across and secured to the passes 4-7 in substantially parallel relation to each other.

The tubular member 2 may be made in any suitable manner from any suitable material, but, preferably, is extruded from aluminum. It embodies an elongated, tubular body portion 12 from the opposite sides of which two elongated, longitudinally extending flanges l3 and 14 project laterally in substantially uniplanar relation to each other, FIG. 2. Each of the flanges 13 and 14 has a plurality of spaced slots 15 formed in the outer longitudinal edge thereof and spaced therealong. In the completed heat exchanger 1, each of the slots 15 in each of the passes 4-7 is disposed in alignment with a respective one of the slots 15 in each of the other of the passes 4-7, and each of the secondary heat transfer elements 11 is disposed on a respective line afforded by a respective alignment of such slots 15.

Eachof the slots 15 embodies an inner portion 16 and an outer portion 17, FIGS. 3 and 4, and in the completed heat exchanger 1, the secondary heat transfer elements 11 are clampingly secured against the portions of the fins 13 and 14 defining the inner portion 16 of the respective slots 15, in which they are disposed, by tabs 18 and 19 struck from the fin material defining the opposite sides of the outer portion 17 of the respective slots 15, as shown in FIG. 3. The tabs 18 and 19 preferably engage the secondary heat transfer elements 11 with a clamping force sufficient to hold the heat transfer elements 11 against movement in the respective slots in which they are disposed, during normal use of the heat exchanger 1.

In the making of the heat exchanger 1, we prefer to extrude the tubular member 2 in elongated, substantially straight form from a suitable material such as the aforementioned aluminum, and then to form the slots 15 therein in a punch press, or the like. The tubular member 2 may then be formed into a suitable pattern, such as the serpentine pattern shown in FIG. 1, by suitable means, such as passing it through a brake press in a direction to form the bends 8-10 transversely to the plane of the flanges 13 and 14, to thereby dispose the passes 4-7 and the return bends 8-10 in uniplanar relation to each other with the flange 13 projecting from one side thereof and the flange 14 projecting from the opposite side thereof. Preferably, in forming the tubular member 2 into the aforementioned serpentine pattern, the bends 8-10 are so constituted and arranged that each of the slots 15 formed in the respective flanges 13 and 14 on each of the passes 47 is disposed in alignment with a slot 15 in the respective flanges l3 and 14 on the other of the passes 4- 7.

At this stage in the preferred method of making the heat exchanger 1, the slots 15 are completely open, as shown in FIGS. 2 and 4. The secondary heat transfer elements 11, made of suitable solid material,.such as, for example, aluminum wire, may then be placed in respective sets of aligned slots on each side of the passes 4-7 and the tabs 18 and 19 may be cut from the flange material adjacent to the outer portion 17 of each slot 15, and turned inwardly into clamping relation to the heat exchanger element 11 disposed in each respective slot 15. This cutting and displacing operation on the tabs 18 and 19 may be performed by suitable means such as a staking tool 20, shown in FIG. 3, in a punch press die or rotary die, or the like. Preferably, the staking operation is accomplished simultaneously on all of the slots 15 disposed on at least one side of the tubular member 2, and, if desired, it may be simultaneously performed on all of the slots 15 disposed in both of the flanges l3 and 14.

We prefer to form the secondary heat transfer elements from wire carried on spools of wire, severing the heat transfer elements 11 from the spools during each staking operation. However, the heat transfer elements 11 may be otherwise formed, such as, for example, by pre-cutting them to length and disposing them in operative position in the slots 15, without departing from the purview of the present invention.

The flanged and slotted tubular members 2, embodied in the heat exchanger 1, may be formed in any suitable manner, such as, for example, by making them individually. However, we prefer to make them by first extruding a set 21 of a plurality of tubular body portions, such as the four tubular body portions 22, shown in FIG. 10, disposed in parallel relation to each other, and interconnected by intermediate flanges 23 extending between each adjacent pair of tubular body portions 22, and with outer flanges 24 and 25, being formed on respective opposite sides of the set 21. The intermediate flanges 23 are twice as wide as the flanges 13 and 14, and the outer flanges 24 correspond in width to the flanges 13 and 14.

After thus forming the set 21, recesses 26, which correspond in size and shape to the slots 15, may be formed in the outer longitudinal edges of the flanges 24 and 25, and elongated openings 27, which have the same width as the slots 15 but are twice as long, may be formed in the intermediate flanges 23 midway between the adjacent tubular members 22, by passing the set 21 through a suitable punch press, or the like, Thereafter, the adjacent tubular members 22 may be separated from each other, by passing the set 21 through a suitable punch press or parting die, to thereby slit the intermediate flanges 23 at the midpoint of the openings 27 and thus afford flanges on each tubular member 22 corresponding to the flanges 13 and 14, with the flanges on the tubular members 22 having slots therein corresponding to the slots 15.

A modified form of the present invention is shown in FIG. 5, and parts which are the same as parts shown in FIGS. 1-4 are indicated by the same reference numerals, and parts which are similar to parts which are shown in FIGS. 1-4 and which have been substituted therefore, are indicated with the same reference numerals with the sufflx a added.

The heat exchanger 1a illustrated in FIG. 5 is identical in construction to the heat exchanger shown in FIGS. 14 except that the heat transfer elements 11a are in the form of tubular members rather than solid members.

The heat exchanger 1a may be made by the same method as heretofore described with respect to the heat exchanger 1, except, that we prefer to pre-cut all of the heat exchanger elements 11a to size prior to inserting the same in the slots in the flanges 13 and 14.

In FIGS. 6 and 7 another modified form of the present invention is shown, and parts which are the same as parts shown in FIGS. 1-4 are indicated by the same reference numerals and parts which are similar to, but have been substituted for the parts shown in FIGS. 1-4 are indicated by the same reference numerals with the suffix b added thereto.

The heat exchanger 1b shown in FIGS. 6 and 7 is identical in construction to the heat exchanger 1 shown in FIGS. l-4 except that the heat transfer elements 11 are clampingly held in the slots 15 in the flanges 13 and 14 by different forms of tabs 18b and 19b. In the heat exchanger 1b, the tabs 18b and 19b, instead of being severed from portions of the flanges l3 and 14 adjacent to the respective slots 15, are, formed by pinching the portions of the flanges 13 and 14 adjacent the respective slots 15, after the heat transfer elements 11 have been disposed in the undeformed slots 15, as illustrated in FIG. 4. Such pinching causes the portions of the flanges 13 and 14 adjacent to the upper portion 17 of each slot 15 to be elongated and extended toward each other across the respective slots 15 to afford the tabs 18b and 19b, which are disposed in firm clamping engagement with the sides of the heat transfer elements 1 l remote from the inner end portion 16 of the respective slots 15.

The preferred method of making the heat exchanger 1b is the same as that heretofore discussed with respect to the heat exchanger 1, shown in FIGS. 1-4, except that, after the heat transfer elements 11 have been disposed in the slots 15, a pinching operation, rather than a staking operation, is performed to secure together the tubular member 2 and the heat transfer elements 11. Such a pinching operation may be performed by any suitable means, such as, for example, by a punch press die or a rotary die.

In FIGS. 8 and 9 another modified form of the present invention is shown, and parts which are the same as parts shown in FIGS. 1-4 are indicated by the same reference numerals, and parts which are similar to, but have been substituted for parts shown in FIGS. 1-4, are indicated by the same reference numerals with the suffix 0 added thereto.

The heat exchanger 1c shown in FIGS. 8 and 9 is identical in construction to the heat exchanger shown in FIGS. 1-4 except that, instead of affording two tabs 18 and 19 at opposite sides of each of the slots 15, a single tab 180 is afforded for clampingly holding the heat exchanger element 11 in the respective slot 15c.

In forming the slots 150 in the flanges l3 and 14 of the heat exchanger 10, the upper portion 17c thereof is not completely removed in the manner shown in FIG. 4 relative to the slot 15, but, rather, the tab 18c is formed by slitting the flange material adjacent one side of the slots 15c, such as at 21, to thereby afford a tab 180 which is attached at one end to the respective flange 13 or 14, and then bendingthe tab 18c the'tabs 180 have thus been turned into outwardly projecting position, the tubular member 2 may be formed into the desired pattern, and the heat transfer elements 11 may be disposed in the slots 150, in the same manner as heretofore discussed with respect to the heat exchanger l, shown in FIGS. 1-4. Thereafter, the tabs 180 may be turned from the outwardly projecting positions shown in broken lines in FIGS. 8 and 9 into the positions shown in solid lines therein, wherein they extend across the outer portions 170 of each of the respective slots in position to clampingly engage the portions of the heat transfer elements 11 remote from the inner portions 16 of the slots 150.

From the foregoing it will be seen that the present invention enables a novel heat exchanger of the aforementioned wire condenser type to be afforded.

In addition, it will be seen that the present invention enables solid heat transfer elements, such as wires, and the like, to be connected to other heat transfer elements in a novel and expeditious manner, although the present invention is not limited to the connection of solid heat transfer elements to other heat transfer elements, but also enables tubular heat transfer elements to be connected to other heat transfer elements in a novel and expeditious manner.

In addition it will be seen that the present invention affords a novel heat exchanger which is practical and efficient in operation, and which may be readily and economically produced commercially, and affords a novel method of making the same.

Thus, while we have illustrated and described the preferred embodiments of our invention, it is to be understood that these are capable of variation and modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.

We claim:

1. A heat exchanger comprising a. an elongated tubular heat transfer element having an opening extending through an outer marginal wall portion transversely to the length of said element,

b. said opening having 1. an inner marginal portion, and 2. an outer marginal portion, and c. a second heat transfer element disposed in said opening in abutting engagement with said marginal portions, 5 d. the portion of said first mentioned heat transfer element defining said outer marginal portion 1. being a severed portion of an adjacent portion of said first mentioned heat transfer element, and 2. clampingly engaging the portion of said second heat transfer element remote from said inner marginal portion in position to hold said second heat transfer element in said abutting engagement with said inner marginal portion.

2. A heat transfer element as defined in claim 1, and in which a. said severed portion comprises two staked portions of said first mentioned heat transfer element disposed on opposite sides of said opening.

3. A heat transfer element as defined in claim I, and in which a. said severed portion comprises a tab member disposed in substantially completely overlying relation to said second heat transfer element on the side thereof remote from said inner marginal portion of said opening. 4. A heat exchanger comprising a. an elongated tubular heat transfer element having an opening extending through an outer marginal wall portion transversely to the length of said element, b. said opening having 1. an inner marginal portion, and 2. an-outer marginal portion, and c. a second heat transfer element disposed in said opening in abutting engagement with said marginal portions, d. the portion of said first mentioned heat transfer element defining said outer marginal portion 1. being a pinched portion of said first mentioned heat transfer element extending across said opening, and 2. clampingly engaging the portion of said second heat transfer element remote from said inner marginal portion in position to hold said second heat transfer element in said abutting engagement with said inner marginal portion. 5. A heat exchanger comprising a. elongated tubular means having I. a plurality of elongated, laterally spaced passes,

and 2. longitudinally extending flange means projecting laterally outwardly from said passes, b. said flange means having openings 1. extending through the outer marginal portions thereof transversely to the length of said flange means, and 2. spaced along said passes, c. said openings on each of said passes being disposed in alignment with openings on other of said passes,

d. elongated solid members 1. extending transversely across said passes, and 2. disposed in said openings e. the portions of said flange means defining said openings clampingly engaging said solid members disposed therein for holding said solid heat transfer elements stationary in said openings.

6. A heat exchanger as defined in claim 5, and in 10 which a. said solid members comprise wires. 7. A heat exchanger as defined in claim 5, and in which a. said solid members are disposed in substantially parallel relation to each other. 8. A heat exchanger as defined in claim 5, and in which a. said tubular means comprises a serpentine-shaped tubular member,

b. said flange means includes a flange extending longitudinally of said tubular member, and

c. said openings comprise slots opening outwardly through a longitudinal edge of said flange.

9. A heat exchanger as defined in claim 5, and in which through longitudinal edges of said flanges. 

1. A heat exchanger comprising a. an elongated tubular heat transfer element having an opening extending through an outer marginal wall portion transversely to the length of said element, b. said opening having
 1. an inner marginal portion, and
 2. an outer marginal portion, and c. a second heaT transfer element disposed in said opening in abutting engagement with said marginal portions, d. the portion of said first mentioned heat transfer element defining said outer marginal portion
 1. being a severed portion of an adjacent portion of said first mentioned heat transfer element, and
 2. clampingly engaging the portion of said second heat transfer element remote from said inner marginal portion in position to hold said second heat transfer element in said abutting engagement with said inner marginal portion.
 2. A heat transfer element as defined in claim 1, and in which a. said severed portion comprises two staked portions of said first mentioned heat transfer element disposed on opposite sides of said opening.
 2. clampingly engaging the portion of said second heat transfer element remote from said inner marginal portion in position to hold said second heat transfer element in said abutting engagement with said inner marginal portion.
 2. an outer marginal portion, and c. a second heaT transfer element disposed in said opening in abutting engagement with said marginal portions, d. the portion of said first mentioned heat transfer element defining said outer marginal portion
 2. clampingly engaging the portion of said second heat transfer element remote from said inner marginal portion in position to hold said second heat transfer element in said abutting engagement with said inner marginal portion.
 2. an outer marginal portion, and c. a second heat transfer element disposed in said opening in abutting engagement with said marginal portions, d. the portion of said first mentioned heat transfer element defining said outer marginal portion
 2. projecting outwardly from opposite sides of said tubular member in substantially uniplanar relation to each other, and c. said openings comprise slots opening outwardly through longitudinal edges of said flanges.
 2. disposed in said openings e. the portions of said flange means defining said openings clampingly engaging said solid members disposed therein for holding said solid heat transfer elements stationary in said openings.
 2. spaced along said passes, c. said openings on each of said passes being disposed in alignment with openings on other of said passes, d. elongated solid members
 2. longitudinally extending flange means projecting laterally outwardly from said passes, b. said flange means having openings
 3. A heat transfer element as defined in claim 1, and in which a. said severed portion comprises a tab member disposed in substantially completely overlying relation to said second heat transfer element on the side thereof remote from said inner marginal portion of said opening.
 4. A heat exchanger comprising a. an elongated tubular heat transfer element having an opening extending through an outer marginal wall portion transversely to the length of said element, b. said opening having
 5. A heat exchanger comprising a. elongated tubular means having
 6. A heat exchanger as defined in claim 5, and in which a. said solid members comprise wires.
 7. A heat exchanger as defined in claim 5, and in which a. said solid members are disposed in substantially parallel relation to each other.
 8. A heat exchanger as defined in claim 5, and in which a. said tubular means comprises a serpentine-shaped tubular member, b. said flange means includes a flange extending longitudinally of said tubular member, and c. said openings comprise slots opening outwardly through a longitudinal edge of said flange.
 9. A heat exchanger as defined in claim 5, and in which a. said tubular means comprises a serpentine-shaped tubular member, b. said flange means comprise two flanges 